SANTA CLARA -- Safety Dashon Goldson received a letter Thursday from the NFL to inform him of a $21,000 fine for an illegal hit on New England Patriots tight end Aaron Hernandez on Sunday night.

Goldson, who said he plans to appeal the fine, was surprised to read in the letter that it was his "third infraction."

"I don't know what third infraction they're talking about," Goldson said. "This is the first time I've ever been hit with a fine besides the one I had on the Rams."

Goldson was fined $7,875 for an unnecessary roughness penalty of sliding St. Louis Rams quarterback Sam Bradford on Dec. 2. Goldson was also fined $7,875 for taunting Seattle running back Marshawn Lynch on Oct. 18.

Goldson was also fined $25,000 last year after getting ejected for fighting with Arizona wide receiver Early Doucet.

He has also received numerous fines for uniform violations, he said, while producing a stack of letters from the league. Goldson said his fines have been for his socks and uniform pants failing to meet the NFL code.

"They've fined me about $70,000 already," said Goldson, who is playing on a one-year contract of $6.212 million as the 49ers' franchise player.

Defensive coordinator Vic Fangio said he believed Goldson's hit Sunday night on Hernandez was legal. When asked if it was an illegal hit, Fangio said, "I don't think so. He wrapped the guy up, hit him in the chest area."

Fangio said officials have told him that they're asked to call the penalty if there are any doubts.

"If it looks bad, the league has told the officials to err on the side of caution," Fangio said. "So, obviously, if it ends up looking like a big hit, sometimes if they don't see it all and it's a bang-bang play, they're going to err on the side of safety and throw the flag."

Earlier this season, the NFL originally suspended Baltimore safety Ed Reed for one game for his third violation in three seasons of the rule prohibiting helmet-to-helmet hits against defenseless players. However, Ted Cottrell, the hearing officer in the appeal, reduced the discipline to a $50,000 fine with no suspension.

Goldson said he will not change his style of play based on the amount of fines he is accruing.

"I don't have time to sit there in the timespan I have as a football player when I'm on the football field to dictate what's clean and what's a not-so-clean hit," Goldson said. "I'm not a dirty player. And that's just that."

Goldson was penalized 15 yards for the hit on Hernandez. On the next play, Hernandez appeared timid as he tried to catch a short pass from quarterback Tom Brady. The pass glanced off Hernandez's hands and was intercepted by Aldon Smith.

"Hits like that get wide receivers the short (arms)," Goldson said. "It's been proven throughout this league for years, and it's been proven since me and Donte (Whitner) have been back there making hits."

When asked if Goldson wants to be known as the biggest hitter in the NFL, he answered, "No, I just want to be known as a good football player."